Lecture Notes on Pallor and Anemia

Introduction

• Discussion on pallor and its association with the flow of oxygenated hemoglobin in superficial vessels.
• Reddish hue indicates normalcy; absence or decrease indicates pallor.

Areas for Assessing Pallor

• Key areas to check for pallor:
  • Anterior rim of the lower palpebral conjunctiva
  • Tongue
  • Nail bed
  • Palm

Causes of Pallor

• Main cause: Anemia
  • Anemia is indicated when oxygenated hemoglobin concentration is low.
• Cutoff for Anemia:
  • Males: Less than 13 grams per percent
  • Females: Less than 10-12 grams per percent

Associated Features of Anemia

• In physical examination for suspected anemia:
  • Check for koilonychia (spoon nails) in iron deficiency anemia.
  • Look for hyperpigmentation of knuckles in vitamin B12 deficiency.
  • Assess for bleeding tendencies which may indicate bone marrow disorders.

Conditions with Pallor but No Anemia

• Pallor may occur due to decreased blood flow rather than anemia:
  • Causes of decreased blood flow:
    • Peripheral vascular disease
    • Left heart failure
    • Shock
• Decreased blood pressure can also cause pallor:
  • Related to conditions such as:
    • Addison's disease
    • Hyperpituitarism
    • Hypothyroidism

Mechanisms Affecting Blood Pressure and Pallor

• Addison's Disease:
  • Decreased cortisol leads to reduced norepinephrine and sympathetic activation, lowering blood pressure.
• Hyperpituitarism:
  • Decreased cortisol results in decreased norepinephrine, reducing blood pressure.
• Hypothyroidism:
  • Decreased thyroxine lowers catecholamine receptor sensitivity, thereby decreasing blood pressure.

Visibility of Pallor

• When is pallor visible?
  • Typically visible if hemoglobin is less than 10 grams per percent.
• Pallor may not be present:
  • In cases where hemoglobin is between 10 and 12 or 10 and 13 grams per percent.

Palm Creases and Pallor Assessment

• Normal pigmentation: Over skin creases is usually more pronounced.
• Severe pallor: Indicated by decreased pigmentation over palm creases compared to surrounding skin, usually correlating with hemoglobin levels less than 8 grams per percent.